TWI498225B - Precursor pulse generation for inkjet printhead - Google Patents

Description

Inkjet print head precursor pulse generation technology Field of invention

This invention relates to ink jet printing techniques, and more particularly to ink jet print head precursor pulse generation techniques.

Background of the invention

In an ink jet printing system, a printhead receives a transmitted signal containing a transmitted pulse from an electronic controller. In one configuration, the transmit signal is fed directly to the nozzles in the printhead. In another configuration, the transmit signal is latched in the printhead and a latched version of the transmit signal is fed to the nozzle to control the ejection of ink droplets from the nozzle.

In either of the above two configurations, the electronic controller of the printer continues to maintain control of all timing associated with the transmitted signal. The timing associated with the transmitted signal is primarily the actual transmitted pulse width and the point in time at which the transmitted pulse occurred. An electronic controller that controls the timing associated with the transmitted signal is good for printing a single line of print heads at a time, because for this type of print head, all that is required is a shot for the print head. The signal controls the ejection of ink droplets from this printhead.

However, one problem encountered with the print head is the number of connections to the printer controller. These connections are sometimes intermittent, and the more connections there are, the lower the reliability of the system. In addition, flexible interconnects are also costly. Finally, ink cut-in can also cause a short between the signals.

Summary of invention

In accordance with an embodiment of the present invention, a method of operating a printhead assembly of an inkjet printer is specifically provided, comprising the steps of: initiating at least one precursor pulse; delivering the at least one precursor pulse to a first a nozzle; removing the at least one precursor pulse from the first nozzle for a predetermined time to create a pause; starting at least one emission pulse after the pause; and delivering the at least one emission pulse to the first nozzle to eject An ink drop.

According to an embodiment of the present invention, a printing system is specifically provided, comprising: a printing head comprising at least one nozzle and an integrated processor; and a front end register coupled to the integrated type The processor is configured to initiate at least one precursor pulse; a stagnant time end register coupled to the integrated processor and configured to initiate at least one predetermined pause period; a register coupled to the integrated processor and configured to initiate at least one transmit pulse; and a controller coupled to the integrated processor and configured to combine the at least one A precursor pulse is delivered to the at least one nozzle, the at least one precursor pulse is removed from the at least one nozzle for the predetermined dwell time, at least one transmit pulse is initiated after the dwell time, and the at least one transmit pulse is sent to The at least one nozzle sprays an ink droplet.

In accordance with an embodiment of the present invention, an integrated processor for a printhead of a printing system is provided, the printhead having at least one nozzle, the integrated processor including: for initiating at least one precursor a member of the pulse; means for delivering the at least one precursor pulse to the at least one nozzle; for removing the at least one precursor pulse from the at least one nozzle for a predetermined period of time to create a stalled member; At least one transmit pulse is initiated after the pause; and the at least one transmit pulse is delivered to the at least one nozzle to eject an ink drop.

Simple illustration

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram showing one embodiment of an ink jet printing system in accordance with the present invention.

Figure 2 is a flow chart showing one embodiment of an ink jet printing system in accordance with the present invention.

Figure 3 is a diagram of one embodiment of an ink jet printhead subassembly or module in accordance with the present invention.

Figure 4 is an enlarged schematic cross-sectional view showing portions of one embodiment of a printhead in the printing system of Figure 1.

Figure 5 is a block diagram showing a portion of an ink jet print head having a firing pulse generator in accordance with an embodiment of the present invention.

Figure 6 is a block diagram showing an exemplary circuit of a portion of an ink jet print head having a transmit pulse generator circuit in accordance with an embodiment of the present invention.

Detailed description of the preferred embodiment

BRIEF DESCRIPTION OF THE DRAWINGS In the following description, reference is made to the accompanying drawings in the claims In this regard, directional terms such as "upper", "lower", "before", "after", "first", "last", etc. are used in conjunction with the orientation of the described schema. It will be appreciated that other embodiments may be utilized and structural changes may be made without departing from the scope of the invention.

Figure 1 illustrates an embodiment of an ink jet printing system 100 in accordance with the present invention. The inkjet printing system 100 includes an inkjet printhead assembly 102, an ink supply assembly 104, a mounting assembly 106, a media delivery assembly 110, and a controller 114. At least one power supply 118 provides power to various electrical components of the inkjet printing system 100. The inkjet printhead assembly 102 includes at least one printhead or printhead die 122 that ejects ink droplets through a plurality of nozzles or nozzles 103 and toward a print medium 112 for printing to the print medium 112. on. The print media 112 can be any type of suitable sheet material, such as paper, cards, slides, Maitreya film, or the like. Typically, the nozzles 103 are configured in one or more rows, or one or more arrays, such that the ink from the nozzles 103 is appropriate as the inkjet printhead assembly 102 and the print medium 112 are moved relative to one another. Sorting the jets causes letters, symbols, and/or other graphics or images to be printed on the print medium 112.

The ink supply assembly 104 supplies ink to the printhead assembly 102 and includes a water reservoir 105 for storing ink. As such, ink can flow from the water reservoir 105 to the inkjet printhead assembly 102. The ink supply assembly 104 and the inkjet printhead assembly 102 can form a one-way ink dispensing system or a recirculating ink dispensing system. In a one-way ink dispensing system, essentially all of the ink supplied to the inkjet printhead assembly 102 is consumed during the printing process. However, in a recirculating ink dispensing system, only a portion of the ink supplied to the printhead assembly 102 is consumed during the printing process. As such, ink that is not consumed during the printing process will return to the ink supply assembly 104.

In one embodiment, the inkjet printhead assembly 102 is stored with an ink supply assembly 104 in an inkjet cartridge or inkjet pen. In another embodiment, the ink supply assembly 104 is separate from the inkjet printhead assembly 102 and is supplied with ink through an interface such as a supply tube to supply ink to the inkjet printhead assembly 102. In either of the two embodiments, the water reservoir 105 of the ink supply assembly 104 can be removed, replaced, and/or backfilled. In one embodiment in which the inkjet printhead assembly 102 is stored in an inkjet cartridge together with the ink supply assembly 104, the water reservoir 105 includes a local reservoir in the crucible and is disposed separately from the crucible. A larger reservoir. In this way, the separate, larger reservoir can be used to fill the local reservoir back and forth. Likewise, these separate, larger water reservoirs and/or local water reservoirs can be removed, replaced and/or backfilled.

The mounting assembly 106 houses the inkjet printhead assembly 102 relative to the media delivery assembly 110, and the media delivery assembly 110 houses the print medium 112 relative to the inkjet printhead assembly 102. Thus, an area between the inkjet printhead assembly 102 and the print medium 112 defines a print zone 108 adjacent the nozzle 103. In one embodiment, the inkjet printhead assembly 102 is a scanning printhead assembly. As such, the mounting assembly 106 includes a latch for moving the inkjet printhead assembly 102 relative to the media delivery assembly 110 to scan the print medium 112. In another embodiment, the inkjet printhead assembly 102 is a non-scanning printhead assembly. As such, the mounting assembly 106 secures the inkjet printhead assembly 102 at a designated location relative to the media delivery assembly 110. Accordingly, media delivery assembly 110 houses print medium 112 relative to inkjet printhead assembly 102.

The electronic controller of printer controller 114 typically includes a processor, firmware, and other printer electronics to control or communicate with inkjet printhead assembly 102, mounting assembly 106, and media delivery assembly 110. The electronic controller 114 receives the data 116 from a host system, such as a computer, and includes memory to temporarily store the data 116. Typically, data 116 is delivered to inkjet printing system 100 along an electrical, infrared, optical or other information transmission path. The data 116 represents, for example, a file and/or file to be printed. As such, the data 116 forms a print job for the inkjet printing system 100 and includes one or more print job commands and/or command parameters.

In one embodiment, the inkjet printhead assembly 102 is a wide array or multi-head printhead assembly. In one embodiment, the inkjet printhead assembly 102 includes a carrier 120 that carries the printhead 122 and the module manager IC 124. In one embodiment, carrier 120 provides electrical communication between printhead die 122, module manager IC 124 and electronic controller 114, and fluid communication between printhead 122 and ink supply assembly 104. .

The printhead assembly 102 can include any suitable number (N) of printheads 122, where N is at least one. The material must be sent to the print head 122 before a print operation can be performed. The information includes, for example, unprinted data and printed material for the print head 122. The printed material includes, for example, nozzle data containing pixel information, such as bitmap printing data. Non-printing materials include, for example, command/status (CS) data, clock data, and/or synchronized data. Status data for the CS data includes, for example, printhead temperature or position, printhead resolution, and/or error notification.

In one embodiment, the logic and driver circuitry is integrated into a module manager integrated circuit (IC) 124 located on the inkjet printhead assembly 102. The electronic controller 114 operates in conjunction with the module manager IC 124 to control the inkjet printhead assembly 102 for ink droplet ejection from the nozzles 103. As such, electronic controller 114 and module manager IC 124 define a pattern of ejected ink drops that form letters, symbols, and/or other graphics or images on print medium 112. The pattern of the ink droplets ejected is determined by the print job command and/or command parameters.

In one embodiment, the wafer-type transmit pulse generator 125 utilizes a start event to initiate the transmission such that the pulse width of the first signal is not critical to energy distribution. In this case, a wafer-type transmit pulse generator 125 is utilized and pre-planned to deliver a single external pulse to generate multiple pulse paths in the printhead assembly 102, and multiple multiple paths are also generated for each route. The pulse acts as a precursor pulse to start the emission sequence. In general, the precursor pulse can include a plurality of pulses to eject ink from the nozzle to enhance thermal performance and/or dot quality. The wafer-type transmit pulse generator 125 with the precursor pulse extends the life of the module manager integrated circuit (IC) 124 and can be used with older, single-shot pulsed inkjet printheads.

For example, a firmware change can be performed on the same controller wafer to produce a more complex transmit signal in the form of a precursor pulse for a newer print head. In addition, different planned pulse widths can be used for multiple nozzle options on the print head. This extends the life of the module manager integrated circuit (IC) 124. In addition, an external launch pad can be eliminated when a precursor pulse is used. In other words, the precursor pulse increases flexibility due to the ability to generate multiple firing pulses on the wafer without the need to add additional pads to the inkjet printhead interface.

Figure 2 is a flow chart showing one embodiment of an ink jet printing system in accordance with the present invention. Referring to FIG. 2 with reference to FIG. 1, in general, first, the printhead controller 114 plans the precursor and transmit pulses into the module manager integrated circuit (IC) 124 through a series of interfaces that have been used for other functions. The wafer type transmit pulse generator 125 is in a pulse width register (step 200). Second, when the printhead assembly 102 is ready for printing, the controller 114 loads the point data in the rows representing the nozzles 103 to define which particular nozzles are to eject ink (step 210). Third, controller 114 initiates a precursor pulse (step 220) and then delivers the precursor pulse to a first nozzle (step 230).

Thereafter, the precursor pulse is removed from the first nozzle for a predetermined time to create a pause (step 240). In one embodiment, the precursor pulses are removed by utilizing and initiating a stagnant time register (described in detail below) that creates the pause. Finally, a firing pulse is initiated after this pause (step 250), and then the firing pulse is delivered to the first nozzle to eject an ink droplet (step 260). In one embodiment, the transmit pulse can be long or short to activate the internal transmit pulse generating circuit.

In one embodiment, the wafer-type transmit pulse generator 125 of the module manager integrated circuit (IC) 124 includes a plurality of separate lines for delivering precursor and transmit pulses to the nozzles 103. In this case, the precursor pulse can be delivered to the inside or outside (external support precursor) for the print head die.

In another embodiment, a single external line is used to deliver the precursor and transmit pulses to the nozzle 103. In this case, the precursor pulse allows for the generation of a transmission pulse that reduces the cost of the system, since multiple transmit signals can be generated from this single external transmit line, thus saving the link.

In one embodiment with a larger print head (four to six ink colors), there is an additional area available due to mechanical constraints, and this area can be used as a free digital design space to enable no additional Increasing the area cost results in a digital transmit pulse. Eliminating extra pads is very important, especially for systems that use multiple printheads because the cost savings are doubled.

Figure 3 is a diagram of one embodiment of an ink jet printhead subassembly or module in accordance with the present invention. In one embodiment, the printhead die 122 are spaced apart and staggered such that the printhead die 122 in one column overlaps the at least one printhead die 122 in the other column. Thus, the inkjet printhead assembly 102 can span a nominal page width, or a page width that is shorter or longer than the nominal page width. In one embodiment, a plurality of inkjet printhead sub-assemblies or modules 300 form an inkjet printhead assembly 102.

These inkjet printhead modules 300 are substantially similar to the printhead assembly 102 described above and each have a carrier 120 that carries a plurality of printhead dies 122 and a module manager IC 124. In one embodiment, the printhead assembly 102 is formed from a plurality of tail-to-tail printhead modules 102, and each of the printhead assemblies 102 has a staggered or stepped profile. Thus, at least one of the printhead dies 122 of an ink jet printhead module overlaps with at least one of the printhead dies 122 of an adjacent printhead module 102.

A portion of an embodiment of a printhead die 122 is schematically illustrated in FIG. The printhead die 122 includes an array of a plurality of print or drop ejection elements 400. The printing element 400 is formed on a substrate 402 having an ink feed slot 410 formed therein. As such, the ink feed slot 410 provides the supply of liquid ink to the printing element 400. Each of the printing elements 400 includes a film structure 404, an aperture layer 406 and a firing resistor 408. The film structure 404 has an ink feed passage 412 formed therein that communicates with the ink feed slot 410 of the substrate 402. The orifice layer 406 has a front end face 414 and a nozzle opening 416 formed in the front end face 414. The orifice layer 406 also has a nozzle chamber 418 formed therein that communicates with the nozzle opening 416 and the ink feed channel 412 of the membrane structure 404. The firing resistor 408 is located in the firing resistor 408 and includes a plurality of wires 420 that electrically couple the firing resistor 408 to a drive signal and ground.

In the printing process, ink flows from the ink feed slot 410 to the nozzle chamber 418 through the ink feed passage 412. The nozzle opening 416 is operatively associated with the firing resistor 408 such that the ink droplets in the nozzle chamber 418 are energized by the firing resistor 408, ie, via the nozzle opening 416 (eg, perpendicular to the face of the firing resistor 408) and toward a column Printed media jets. In one embodiment, at least one of the printheads 122 is implemented as a printhead having the ability to simultaneously print a number of rows of the same color or a number of rows of different colors.

Exemplary embodiments of the printhead 122 include a thermal printhead, a piezoelectric printhead, a flexographic printhead, or any other type of inkjet spray device known in the art. In one embodiment, the printhead die 122 is a fully integrated thermal inkjet printhead. As such, the substrate 402 can be formed, for example, of tantalum, glass, or a stabilized polymer, and the thin film structure 404 is made of hafnium oxide, tantalum carbide, tantalum nitride, tantalum, polyfluorene, or other suitable materials. One or more passivation layers or insulating layers are formed. The film structure 404 also includes a conductive layer that defines the emitter resistor 408 and the wire 420. This conductive layer is formed, for example, of aluminum, gold, tantalum, aluminum, or other metals or metal alloys.

Figure 5 is a block diagram showing a portion of an ink jet print head having a firing pulse generator in accordance with an embodiment of the present invention. The transmit pulse generator 500 similar to the transmit generator 125 of FIG. 1 includes a controller 510, a front end register 520, a dead time end register 530, a transmit end register 540, a time counter 550, and a nozzle 560. It is similar to the nozzle 103 of FIG. The precursor register 520 sends the precursor pulse to the controller 510, and the transmitter register 540 sends the transmit pulse to the controller 510, and the stagnant time end register sends the pause to the controller 510. And a clock with time counter 550 sends the timing signal to controller 510. The controller utilizes these timing signals to deliver a final composite firing pulse to the nozzle at a predetermined time, including precursor pulses, firing pulses, and pauses to effectively control nozzle 560 emissions.

Figure 6 is a block diagram showing an exemplary circuit of a portion of an ink jet print head having a transmit pulse generator circuit in accordance with an embodiment of the present invention. With reference to FIG. 6 with reference to FIG. 5, in an exemplary embodiment The transmit pulse generator loop 600 includes the precursor register 520 as a precursor pulse (PCP) width register 602 to create a precursor pulse. Similarly, the stagnant time end register 530 is a dead time (DT) width register 610 to create a pause between the precursor pulse and the transmit pulse, and the transmit end register 540 is a transmit width pulse. To create a firing pulse. In one embodiment, the wafer-type transmit pulse generator loop 600 includes counters for respective individual width registers, such as parallel load down counters 630, 640 and 650, to calculate start and end times.

In addition, comparators 660, 670 and 680 are coupled to individual counters 630, 640 and 650 and determine the count for each individual counter. When the count from counter 630 reaches zero, the precursor pulse from PCP width register 602 is sent to operational logic 690, and when the count from counters 640 and 650 reaches zero, the DT width is temporarily The pause of the register 610 and the transmit pulse from the transmit width pulse are sent to the operational logic 695 to deliver the individual pulses or pauses to the nozzle 560.

In one embodiment, the internal pulse generator circuit generates precursor and transmit pulses that are routed to the appropriate nozzles. Alternatively, separate internal pulse generation circuits can be utilized to generate the precursor and transmit pulses, respectively. For example, in one embodiment, a transmit pulse generator can be used for the entire printhead. In another embodiment, two or more pulse generators may be utilized to support multiple pulses and different drop weights/ink types. In one embodiment, the precursor and transmit pulse widths are dynamically planned and immediately double buffered. This frees all re-planning from interrupting the current printing and enabling efficient printing.

In another embodiment for a smaller transmit generator loop, a single counter and a single register can be utilized. In this case, a single counter represents the time during which the pulse toggles from one current state to another or to an opposite state. In another embodiment, a cascade counter is used and the register represents the actual pulse width versus upconversion time. In this case, the internal transmit pulse generator saves connectivity (additional transmit pads) when more than one transmit pulse width is required. In addition, a more complex pulse can be generated, even when an external controller cannot provide such an option. Finally, since only one start-up transmit signal is used, other external methods can be used to initiate the launch, thus completely eliminating the external transmit pad.

In another embodiment, the precursor pulse shares the same wiring as the firing pulse when an individual pulse is delivered to the nozzle. In another embodiment, the precursor pulse will be delivered to the nozzle via the precursor pulse wiring, and the transmit pulse will be delivered to the nozzle via separate and distinct transmit pulse wiring. The separate wiring allows for greater control over the timing between the precursor pulse and the transmitted pulse, which helps to control and optimize the power distribution in the print head. In another embodiment, an externally supported transmit signal can represent a precursor pulse width, wherein the falling edge of the pulse initiates a stagnant time counter and a transmit time counter (a pulse applied to a single nozzle firing event) Between time).

In one embodiment, for the streamlined data input and output of the wafer type transmit pulse generator 125, the wafer type transmit pulse generator 125 completely eliminates the need for external transmit pulses. In one embodiment, depending on the particular implementation and the number of circuit replicas on the printhead die, a plurality of different transmit burst streams can be sent to the module manager integrated circuit driven by the data input. Different areas of the IC 124, and several launch pads are required.

The principles, embodiments and modes of operation of the present invention have been described above. However, the invention should not be construed as being limited to the particular embodiments discussed. The above-described embodiments are to be considered as illustrative and not restrictive, and are to be construed as the scope of the invention as defined by the following claims Many variations in these examples.

100‧‧‧Inkjet printing system

102‧‧‧Print head assembly/print head module

103, 560‧ ‧ nozzle

104‧‧‧Ink supply components

105‧‧‧Water storage tank

106‧‧‧Installation components

108‧‧‧Printing area

110‧‧‧Media transport components

112‧‧‧Printing media

114, 510‧‧ ‧ controller

116‧‧‧Information

118‧‧‧Power supply

120‧‧‧ Carrier

122‧‧‧Print head/print head die

124‧‧‧Module Manager Integrated Circuit (IC)

125‧‧‧ wafer type emission pulse generator

200~260‧‧‧ steps

300‧‧‧Inkjet printing head subassembly/inkjet print head module

400‧‧‧Printing components/droplet ejection elements

402‧‧‧Substrate

404‧‧‧ film structure

406‧‧ ‧ hole layer

408‧‧‧fire resistance

410‧‧‧Ink feed slot

412‧‧‧Ink feed channel

414‧‧‧ front end

416‧‧‧ nozzle opening

418‧‧‧Nozzle chamber

420‧‧‧ wire

500‧‧‧transmit pulse generator

520‧‧‧Precursor register

530‧‧‧Stagnation time end register

540‧‧‧Transmitter register

550‧‧ ‧ time counter

600‧‧‧transmit pulse generator loop

602‧‧‧Precursor Pulse (PCP) Width Register

610‧‧‧Definite Time (DT) Width Register

620‧‧‧ emission width pulse

630~650‧‧‧ counter

660~680‧‧‧ comparator

690~695‧‧‧Operational logic

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram showing one embodiment of an ink jet printing system in accordance with the present invention.

Figure 2 is a flow chart showing one embodiment of an ink jet printing system in accordance with the present invention.

Figure 3 is a diagram of one embodiment of an ink jet printhead subassembly or module in accordance with the present invention.

Figure 4 is an enlarged schematic cross-sectional view showing portions of one embodiment of a printhead in the printing system of Figure 1.

Figure 5 is a block diagram showing a portion of an ink jet print head having a firing pulse generator in accordance with an embodiment of the present invention.

Figure 6 is a block diagram showing an exemplary circuit of a portion of an ink jet print head having a transmit pulse generator circuit in accordance with an embodiment of the present invention.

500‧‧‧transmit pulse generator

510‧‧‧ Controller

520‧‧‧Precursor register

530‧‧‧Stagnation time end register

540‧‧‧Transmitter register

550‧‧ ‧ time counter

560‧‧‧Nozzles

Claims (5)

An ink cartridge comprising an ink jet print head assembly and an ink supply assembly, the ink jet print head assembly comprising an integrated emission pulse generator and a print head having at least one nozzle, the integrated type The transmit pulse generator includes: means for generating at least one precursor pulse; means for delivering the at least one precursor pulse to the at least one nozzle; for removing the at least one precursor pulse from the at least one nozzle a predetermined period of time to create a pause component; a member for generating at least one firing pulse after the pause; and means for delivering the at least one firing pulse to the at least one nozzle to eject an ink droplet. The ink cartridge of claim 1, wherein the at least one precursor pulse shares the same wiring as the at least one firing pulse to deliver the individual pulses to the at least one nozzle. The ink cartridge of claim 1, wherein the at least one precursor pulse is sent to the at least one nozzle through the precursor pulse wiring, and the at least one emission pulse is transmitted through the transmission pulse wiring separately and different from the precursor pulse wiring. Delivered to the at least one nozzle. The ink cartridge of any one of claims 1 to 3, wherein the means for generating the at least one precursor pulse comprises assembling to activate at least one precursor pulse of the precursor register, wherein the at least one precursor pulse is used From this to Having one less nozzle removed for a predetermined period of time includes a set of stagnant time end registers that are configured to initiate a pause of the predetermined period of time, and wherein the at least one transmit pulse is generated to the at least one nozzle to eject a The member of the ink drop includes a firing end register configured to activate at least one firing pulse, the ink cartridge comprising a controller configured to deliver the at least one precursor pulse to the at least one nozzle, The at least one precursor pulse is removed from the at least one nozzle for the predetermined pause, at least one firing pulse is initiated after the pause, and the at least one firing pulse is delivered to the at least one nozzle to eject an ink droplet. The ink cartridge of claim 4, further comprising a clock having a time counter that is configured to transmit a timing signal to a controller.